The proposed research will examine the chemotaxis of phagocytic cells in response to agents that are likely to be involved in airway disease. Therapeutic lung lavage effluent will be used as a source of human airway chemotactic mediators and inhibitors, and airway phagocytic cells, especially alveolar macrophages. Data on human secretory material will be supplemented by studies of rabbit alveolar macrophages and investigations of major classes of chemotactic agents, including: cellular debris, bacterial secretions, inhaled toxins, products of hemostasis, and synthetic cytotaxins. The chemotactic properties of lipids and lipid-protein complexes will receive special attention in order to augment our current knowledge concerning the role of proteins and polypeptides in chemotaxis. Chemotayxis will be assayed quantitatively using a modification of the Boyden Chamber. Qualitative chemotaxis studies will be conducted using the microcinematographic laser technique of Bessis.